Half-Life Beat in Less than 21 Minutes - New World Record

Youtube user quadrazid have, after almost 4 years of careful and painstaking planning, managed to beat their previous speed-run record (of 29 minutes and 41 seconds) by exactly 9 minutes.

Here’s how they describe their efforts:

Not only do we owe this new world-record time to all the new tricks we’ve discovered, the new routes we’ve found and the new ways we’ve
learned to manipulate the game. A lot of the improvement from the first estimation and the previous world record (29 minutes, 41 seconds)
comes from the very hard work and countless hours put into perfecting each and every segment, no matter how short or trivial. This run has
truly been an endurance test for everyone involved, and we’re extremely happy to finally be able to share it with you.

 

Check out their speed-run: